The aim of this study was to explore test-retest reliability, agreement, and responsiveness of questionnaires on productivity loss (iPCQ-VR) and healthcare utilisation (TiCP-VR) for sick workers with chronic musculoskeletal pain who were referred to vocational rehabilitation.Methods
Test-retest reliability and agreement was assessed with a two-week interval. Responsiveness was assessed at discharge after a 15 week vocational rehabilitation (VR) program. Data was obtained from six VR centres in the Netherlands. Test-retest reliability was calculateed with intraclass correlation coefficient (ICC) and Cohen’s kappa. Agreement was calculated by Standard Error of Measurement, Smallest detectable changes (on group and individual level), and percentage observed, positive and negative agreement. Responsiveness was calculated with area under the curve (AUC) obtained from receiver operation characteristic (ROC).Results
A sample of 52 participants on test-retest reliability and agreement and a sample of 223 on responsiveness were included in the study. Of the iPCQ-VR, ICCs ranged from 0.52 to 0.90, kappa ranged from 0.42 to 0.96, and AUC ranged from 0.55–0.86. The ICC of total healthcare utilisation of the TiCP-VR was 0.81 and kappa values of the single healthcare utilisation items ranged from 0.11 to 1.Discussion
The iPCQ-VR showed good clinimetric properties on working status, number of hours working per week and long term sick leave, and low measurement properties on short term sick leave and presenteeism. The TiCP-VR showed adequate reliability on all healthcare utilisation items together and medication use, but showed low clinimetric properties on the single healthcare utilisation items.